Washington Neural Tube Defect Cluster Investigated By CDC

Health experts are investigating an unusual number of infants born with neural tube defects in central Washington state.

In the September 2013 issue of it’s Morbidity and Mortality Weekly Report (MMWR), the U.S. Centers for Disease Control and Prevention (CDC) issued a field report on an ongoing investigation into a cluster of birth defects involving neural tube defects.

Concerns were raised by a health-care provider in August 2012, after an excessive number of anencephaly births, which involve serious defects where the baby is born without parts of the brain and skull. Also known as neural tube defects, these problems often arise during the first month of pregnancy, which is a time when many women do not even know they are pregnant.

Neural tube defects typically affect about one in every 1,000 births in the U.S. They are characterized by a hole in the spinal cord or brain because the neural tube does not close completely. This can result in defects that include spina bifida, and brain malformations that may result in parts of the brain missing or protruding from the skull.

Following reports of the birth defect cluster, CDC investigators looked at data from the area and found 27 confirmed cases of neural tube defect-affected pregnancies in a three-county area from January 2010 to January 2013. They found that 23 of the cases involved cases where the fetus developed without a major portion of the brain, skull or skull cap, which is almost always fatal. The other four cases included three incidents of spina bifida and one case of encephalocele.

The CDC investigators have determined that the anencephaly rate was 8.4 per 10,000 live births, which is four times the national rate of 2.1 per 10,000 live births.

Further research and investigations at 13 area prenatal clinics has not been able to determine the cause of the increased neural tube defect rates. As a result, the CDC is continuing active surveillance of births in the area throughout the rest of the year and the Washington Department of Health is reminding doctors about the importance of folic acid supplements for women of child-bearing age. Good folic acid levels are considered critical in the prevention of neural tube defects.